Novak Djokovic, Maria Sharapova sparkle after others toil at US Open

(From top) Andy Murray, Maria Sharapova, Novak Djokovic and Venus Williams comfortable sailed into the next round at the US Open.

Former champions Novak Djokovic and Maria Sharapova sparkled under the Arthur Ashe Stadium lights to end a steamy first day that proved more than a little stressful for several of the US Open favourites on Monday.

Djokovic, who had won only two matches in the hard court run-up to the season's final grand slam after getting married just days after his Wimbledon triumph, was back to his best once the center court spotlight shone on him at Flushing Meadows.

The 2011 champion treated his first-round match against unseeded 22-year-old Argentine Diego Schwartzman like a breezy workout, dominating in all phases with 24 winners including seven aces in a 6-1 6-2 6-4 rout.

His fast work followed a scintillating finish by French Open champion and 2006 winner Sharapova, as the fifth seed won 10 straight games to prevail 6-4 6-0 after falling 2-4 behind against her Russian compatriot and old friend Maria Kirilenko.

Despite the night programme starting one hour later than scheduled due to ceremonies featuring bands, speeches and fireworks, Djokovic enabled the New York night crowd to head to the exits shortly before the stroke of midnight.

"I'm very pleased," the Serbian world number one said in a courtside interview after his 97-minute win. "It's never easy to start a U.S. Open smoothly."

Several of the favorites at Flushing Meadows could attest to his opinion.

Busy bees made life difficult for two grizzled veterans and a pair of favourites were forced to work overtime on a hot, steamy day at the U.S. National Tennis Center that drew a combined 57,000 fans to the day and night sessions.

Eighth-seeded 2012 champion Andy Murray fought off cramps to beat Dutchman Robin Haase in four painful sets, while women's second seed Simona Halep lost an early tiebreak to U.S. debutant Danielle Collins before claiming victory.

And in an intriguing match-up of 19th seed Venus Williams and Kimiko Date-Krumm of Japan, the oldest players in the women's draw, some pesky bees joined in and refused to leave them alone.

MAJOR CRAMPING

Murray appeared on course for an easy victory before he fell victim to cramps that left him stretching and straining to get comfortable before clinching a 6-3 7-6 (6) 1-6 7-5 victory over Haase.

"I felt extremely good before the match, and I did train very, very hard to get ready for the tournament," said Murray, one of the fittest players on the ATP Tour. "My quads were cramping, then it started to get to my lats, then my forearms," he added. "I just tried to hang around and at the end I was trying to play without moving my legs much and managed to get through."

Murray said he might consult with a nutritionist before meeting his second-round opponent, Germany's Matthias Bachinger.

A less serious intrusion hit the irresistible women's clash between seven-times grand slam singles winner Williams and Japan's remarkable Date-Krumm, who were beset by bees. First the 43-year-old Japanese player and later 34-year-old Williams dipped, ducked and danced away before ballgirls helped usher the stubborn swarm away from the baseline.

When finally left to play tennis on a sun-bathed Arthur Ashe Stadium court, Williams stung her opponent 2-6 6-3 6-3 to advance. Asked about who presented the peskier test in the two-hour match, two-time U.S. Open winner Williams said: "The bee was a challenge but easily the answer is Kimiko."

EARLY UPSET

In an upset on the men's side, twice US Open semi-finalist Mikhail Youzhny of Russia, the 21st seed, fell to big-serving Australian teenager Nick Kyrgios 7-5 7-6 (4) 2-6 7-6 (1). The 19-year-old Kyrgios, who made a Wimbledon splash by ousting Rafa Nadal in the fourth round to reach the quarter-finals, blasted 26 aces. The 60th-ranked Kyrgios moved on to a second-round match against Italy's Andreas Seppi.

Advancing with relative ease in straight sets were Australian Open champion Stan Wawrinka of Switzerland and fifth-seeded Canadian Milos Raonic, a Wimbledon semi-finalist.

The Swiss third seed beat Jiri Vesely of the Czech Republic to set up a second-round test against Brazilian Thomaz Bellucci, while big-serving Raonic defeated Japan's Taro Daniel to get to the next round against Peter Gojowczyk of Germany.

Halep survived a scare in the tournament's first match on stadium court before overtaking Collins 6-7 (2) 6-1 6-2. The 22-year-old Romanian, a French Open finalist, admitted to a bout of nerves in being thrust onto the big stage as the opening act of the season's last grand slam.

"She played a tough match, I want to congratulate her," Halep said of her 20-year-old opponent, who was given a wild card into her first tour-level event for winning the US collegiate championship. The first set I was a little bit nervous. This court is huge. I have to enjoy it, but it's not easy. Everybody is telling me I have chances to win this title."

She moves on to face Slovakian Jana Cepelova, a 2-6 7-5 6-1 winner over Spain's Maria-Teresa Torro-Flor, in the second round of the season's last grand slam.

Also advancing on the women's side were fourth seed Agnieszka Radwanska of Poland, sixth seed Angelique Kerber of Germany, and former world number one Jelena Jankovic of Serbia, the ninth seed.